Critical-condition monitoring apparatus for capacitive devices, and monitoring method

Abstract

Disclosed in the present invention are a critical-condition monitoring apparatus for capacitive devices, and a monitoring method. The critical-condition monitoring apparatus comprises a measurement unit, which comprises a collection module, and a conversion module electrically connected to the collection module; a processing module, which is electrically connected to the measurement unit; and an output module, which is electrically connected to the processing module. The critical-condition monitoring apparatus for capacitive devices can learn the insulation status of an abnormal device in a timely manner, thereby reducing operational risks of a grid caused by the device operating under defective conditions; the apparatus can replace the periodic re-testing for abnormal devices, which significantly reduces the manpower and material resource consumption, and also reduces personnel safety risks during re-testing; and the apparatus achieves the performance of online monitoring and reducing costs. In addition, the apparatus is movable and is deployable across multiple substations.

Description

A capacitive device for critical care monitoring and a monitoring method Technical Field

[0001] This invention relates to the field of power grid monitoring technology, and in particular to a critical monitoring device and method for capacitive equipment. Background Technology

[0002] Monitoring the insulation performance of capacitive equipment without power outages has become an essential technical means for power grid development. It improves the timeliness and reliability of defect detection in capacitive equipment, and this technology is now widely used. Currently, there are two main monitoring methods in the power grid: periodic live-line monitoring and pre-testing, and the installation of online monitoring devices. Live-line monitoring has drawbacks such as a small accumulation of abnormal data when equipment data is abnormal, making real-time monitoring of abnormal equipment status impossible, and posing safety risks during retesting. Online monitoring suffers from high costs and high failure rates. For example, for individual devices such as current transformers and voltage transformers, the installation and maintenance cost of an online monitoring system may exceed the value of the main equipment itself. Summary of the Invention

[0003] In view of the problems existing in the above-mentioned capacitive equipment critical care monitoring devices, the present invention is proposed.

[0004] Therefore, the purpose of this invention is to provide a capacitive device for critical care monitoring, which aims to solve the problems of high cost and high failure rate mentioned above.

[0005] In a first aspect, the present invention provides the following technical solution: a capacitive device for critical care monitoring, comprising,

[0006] The measurement unit includes a data acquisition module and a conversion module electrically connected to the data acquisition module;

[0007] A processing module electrically connected to the measurement unit; and,

[0008] An output module electrically connected to the processing module.

[0009] As a preferred embodiment of the capacitive equipment critical care monitoring device of the present invention, the conversion module includes a resistor module R and a surge arrester F electrically connected to the resistor module R;

[0010] The output terminal of the surge arrester F is electrically connected to the acquisition module.

[0011] As a preferred embodiment of the capacitive equipment critical care monitoring device of the present invention, the acquisition module includes a current transformer (CT) and an analog-to-digital converter (A / D) electrically connected to the output terminal of the current transformer (CT).

[0012] The input terminal of the current transformer CT is electrically connected to the output signal In and the input signal Ix, respectively.

[0013] The acquisition module is configured in two sets.

[0014] In a preferred embodiment of the capacitive device for critical care monitoring described in this invention, the input terminal of the processing module is electrically connected to the analog-to-digital converter (A / D).

[0015] The processing module performs transformation processing using the FFT algorithm to obtain the fundamental phase Ph(ns) and the fundamental phase Ph(xs).

[0016] As a preferred embodiment of the capacitive device for critical care monitoring described in this invention, the output module is used to calculate the phase difference Ph, wherein the formula for calculating the phase difference Ph is: Ph = Ph(xs) - Ph(ns);

[0017] Next, the dielectric loss Tanδ is calculated using the following formula:

[0018] As a preferred embodiment of the capacitive device critical care monitoring device of the present invention, the current transformer CT adopts a through-hole structure and the through-hole diameter is Φ25mm.

[0019] Secondly, the present invention provides the following technical solution: a monitoring method for a capacitive device for critical care monitoring, comprising the following steps,

[0020] Install critical care monitoring devices to acquire monitoring information;

[0021] The acquired detection information is processed to obtain stable information;

[0022] The dielectric loss is obtained by calculating the stable information.

[0023] As a preferred embodiment of the monitoring method of the capacitive equipment critical care monitoring device of the present invention, when acquiring detection information, a monitoring duration threshold is set. When the monitoring duration is less than the threshold, it is judged as short-term monitoring; when the monitoring duration is not less than the threshold, it is judged as long-term monitoring.

[0024] As a preferred embodiment of the monitoring method for the intensive care monitoring device of the capacitive equipment described in this invention, the processing of the acquired detection information includes the following steps:

[0025] Choose between standalone measurement mode or online measurement mode;

[0026] The steps of the single-machine measurement mode include: using a single critical care monitoring device for testing, and entering the single-machine test in the settings interface, selecting capacitive equipment or surge arrester according to the type of equipment being tested;

[0027] The steps of the online measurement mode include: connecting a single critical care monitoring device and the operating equipment, entering the selection interface and setting it to synchronization mode.

[0028] As a preferred embodiment of the monitoring method of the capacitive equipment critical care monitoring device of the present invention, wherein: when installing the critical care monitoring device, the side of the cable with the shielded grounding end is connected to the current input terminal inside the critical care monitoring box, and the shielded grounding end is connected to the grounding bolt of the critical care monitoring box;

[0029] Remove the plug from the pre-drilled inlet hole at the bottom of the live test terminal box and install a waterproof connector;

[0030] The other end of the signal cable passes through the waterproof connector of the live test terminal box and is connected to the terminal block therein;

[0031] Tighten the waterproof connectors at the cable inlets of the live test terminal box and the intensive care monitoring box;

[0032] After the cable connection is completed, open the shorting tabs and knife switches of the live test terminal box in sequence.

[0033] Wiring steps for reference unit voltage input:

[0034] After the critical care monitoring box is securely fixed, first connect the side of the cable with the shielded grounding end to the voltage input terminal inside the critical care monitoring box, and connect the shielded grounding end to the grounding bolt of the monitoring box;

[0035] The other end of the signal cable is connected to the secondary terminal of the PT on the same busbar as the device under test.

[0036] Tighten the waterproof connector at the cable inlet of the critical care monitoring box.

[0037] The beneficial effects of this invention are: it can promptly grasp the insulation status of abnormal equipment, reducing the power grid operation risks caused by equipment operating with defects; it replaces the periodic retesting of abnormal equipment, saving a lot of manpower and resources; it reduces the personal risks during the retesting of abnormal equipment; it can achieve the effect of online monitoring, saving costs; it is mobile and can be applied to multiple substations in rotation. Attached Figure Description

[0038] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein:

[0039] Figure 1 is a schematic diagram of the overall structure of the capacitive device for critical care monitoring of the present invention.

[0040] Figure 2 is a flowchart illustrating the monitoring method of the capacitive equipment critical care monitoring device of the present invention.

[0041] Figure 3 is a schematic diagram of the test unit operation interface of the monitoring method of the capacitive equipment critical care monitoring device of the present invention.

[0042] Figure 4 is a schematic diagram of the remote transmission setting interface of the monitoring method of the capacitive equipment critical care monitoring device of the present invention.

[0043] Figure 5 is a schematic diagram of the test software interface of the monitoring method of the capacitive equipment critical care monitoring device of the present invention.

[0044] Figure 6 is a schematic diagram of the system configuration interface of the monitoring method of the capacitive equipment critical care monitoring device of the present invention. Detailed Implementation

[0045] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0046] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0047] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that is mutually exclusive with other embodiments.

[0048] Secondly, the present invention is described in detail with reference to the schematic diagrams. When detailing the embodiments of the present invention, for ease of explanation, the cross-sectional views illustrating the device structure may be partially enlarged, not according to the usual scale. Furthermore, the schematic diagrams are merely examples and should not limit the scope of protection of the present invention. In addition, actual fabrication should include three-dimensional spatial dimensions of length, width, and depth.

[0049] Example 1

[0050] Referring to Figure 1, which illustrates the first embodiment of the present invention, a capacitive device for critical care monitoring is provided. This device includes,

[0051] The measurement unit includes a data acquisition module and a conversion module electrically connected to the data acquisition module;

[0052] A processing module electrically connected to the measurement unit; and,

[0053] An output module electrically connected to the processing module.

[0054] Furthermore, the conversion module includes a resistor module R and a surge arrester F electrically connected to the resistor module R;

[0055] The output terminal of the surge arrester F is electrically connected to the acquisition module;

[0056] The conversion module is configured to convert the secondary voltage signal Un of the bus PT into a current signal In.

[0057] Furthermore, the acquisition module includes a current transformer (CT) and an analog-to-digital converter (A / D) electrically connected to the output terminal of the current transformer (CT).

[0058] The input terminal of the current transformer CT is electrically connected to the input signal In and the output signal Ix, respectively.

[0059] The acquisition module is configured in two sets;

[0060] By configuring the acquisition module, the current signal In is collected, and because two sets are configured, the current signal Ix of the last screen is also collected synchronously.

[0061] The input terminal of the processing module is electrically connected to the analog-to-digital converter (A / D).

[0062] The processing module performs transformation processing using the FFT algorithm to obtain the fundamental phase Ph(ns) and the fundamental phase Ph(xs);

[0063] When the fundamental phase Ph(ns) and fundamental phase Ph(xs) are calculated, the monitoring data can be output, which makes it convenient for staff to query the equipment under test.

[0064] Furthermore, the output module is used to calculate the phase difference Ph, where the formula for calculating the phase difference Ph is: Ph = Ph(xs) - Ph(ns);

[0065] Next, the dielectric loss Tanδ is calculated using the following formula:

[0066] By setting the calculation formulas for phase difference Ph and dielectric loss Tanδ, the accuracy of the calculation results is ensured.

[0067] Furthermore, the current transformer (CT) adopts a through-hole structure with a through-hole diameter of Φ25mm.

[0068] When detecting power frequency current signals ranging from 100μA to 1000mA, the phase transformation error is no greater than ±0.01° and is unaffected by ambient temperature and electromagnetic interference, fundamentally solving the problem of accurate sampling of current signals at the end screen of capacitive equipment.

[0069] In operation, the dielectric loss measurement of capacitive equipment typically requires the bus voltage as the reference for phase measurement. The traditional approach is to directly provide the secondary voltage signal of the bus PT to the detection system. The main drawbacks are complex field wiring, susceptibility of the reference voltage signal to electromagnetic interference during long-distance transmission (potentially distorting the dielectric loss measurement results), and difficulty in ensuring sampling safety. Leveraging advanced fieldbus control technology and high-precision phase measurement technology, the SIM3 monitoring system pioneered and adopted a novel phase comparison measurement method, as shown in Figure 1. This method effectively solves the sampling problem of the reference voltage signal and accurately determines the phase difference between the fundamental components of the two measured current signals.

[0070] The secondary voltage signal Un of the bus PT is transformed into a current signal In through resistor R, which is detected by the reference unit installed below the PT. The final screen current signal Ix of the capacitive equipment is detected by the measurement unit. Under the control of the central processing unit, the signal acquisition systems of the two measurement units are started simultaneously, and the analog voltage signals output by the sensors are sampled and processed by FFT to obtain the fundamental phase Ph(ns) and fundamental phase Ph(xs) of the input signals Un and Ux relative to the 220Vac power supply Us.

[0071] The central processing unit reads the corresponding phase measurement results and can calculate the phase difference Ph between the capacitive equipment's end-screen current signal Ix and the bus voltage Un, thereby obtaining its dielectric loss Tanδ and capacitance Cx and other insulation parameters.

[0072] Example 2

[0073] Referring to Figure 1, a second embodiment of the present invention differs from the first embodiment in that it includes a monitoring method for a capacitive device for critical care monitoring, comprising the following steps:

[0074] S1. Install the critical care monitoring device and obtain monitoring information.

[0075] S2. Process the acquired detection information to obtain stable information.

[0076] When acquiring detection information, a monitoring duration threshold is set. If the monitoring duration is less than the threshold, it is judged as short-term monitoring; if the monitoring duration is not less than the threshold, it is judged as long-term monitoring.

[0077] For example, in short-term monitoring, simply fix two units of the monitoring system near the device to be monitored, connect the signal, and the system will periodically measure the device under test and transmit the monitoring data to the back-end system wirelessly. This not only improves work efficiency but also greatly reduces production costs. By classifying and judging, it can achieve the effect of saving costs.

[0078] Processing the acquired detection information includes the following steps:

[0079] Choose between standalone measurement mode or online measurement mode;

[0080] The steps of the single-machine measurement mode include: using a single critical care monitoring device for testing, and entering the single-machine test in the settings interface, selecting capacitive equipment or surge arrester according to the type of equipment being tested;

[0081] The steps of the online measurement mode include: connecting a single critical care monitoring device and an operating device (such as a laptop computer), entering the selection interface and setting it to synchronization mode;

[0082] In this embodiment, as shown in Figure 3, after the test unit completes its power-on self-test, a test mode selection interface will pop up. If the user does not operate within 5 seconds, the default mode will be used. When controlling a single instrument for stand-alone testing via a laptop, a network cable should be used to connect the laptop and the test unit. The test unit must be set to "stand-alone test" mode. After entering the main interface displayed by the test unit, the current sampling method "channel-rate" will be displayed. Press the "↑" or "↓" key to enter the settings interface, select "synchronization mode" to set the rate, and then enter the channel selection. When testing online, the synchronization mode (rate, channel) of the main control unit must be consistent with that of the controlled unit. It is recommended to prioritize the high-speed communication mode. If the signal is unstable, then select the medium-speed or low-speed mode in turn.

[0083] In stand-alone measurement mode, press the "↑" or "↓" key on the main instrument interface to enter the settings interface, select "stand-alone test", select "capacitive device" or surge arrester according to the type of device under test, and press the "OK" key to start or stop the measurement. During stand-alone measurement, the CH1 channel of the main control unit (or controlled unit) should be connected to the reference signal, and the CH2 channel should be connected to the signal under test.

[0084] When installing the critical care monitoring device, connect the side of the cable with the shielded grounding end to the current input terminal inside the critical care monitoring box, making sure that the phase and wire core colors match, and connect the shielded grounding end to the grounding bolt of the critical care monitoring box;

[0085] Remove the plug from the pre-drilled inlet hole at the bottom of the live test terminal box and install a waterproof connector;

[0086] The other end of the signal cable passes through the waterproof connector of the live test terminal box and is connected to the terminal block therein. Note that the phase and wire core colors should correspond.

[0087] Tighten the waterproof connectors at the cable inlets of the live test terminal box and the intensive care monitoring box;

[0088] After the cable connection is completed, open the shorting tabs and knife switches of the live test terminal box in sequence.

[0089] Wiring steps for reference unit voltage input:

[0090] After the critical care monitoring box is securely fixed, first connect the side of the cable with the shielded grounding end to the voltage input terminal inside the critical care monitoring box, making sure that the phase and wire core colors match. Connect the shielded grounding end to the grounding bolt of the monitoring box.

[0091] The other end of the signal cable is connected to the secondary terminal of the PT on the same busbar as the device under test. Note that the phase and the wire core colors should correspond.

[0092] Tighten the waterproof connector at the cable inlet of the critical care monitoring box.

[0093] In this embodiment, remote transmission settings are also required, including enabling router NAT port mapping: Log in to the local area network router through the computer receiving the data. The router IP is usually 192.168.1.1. Go to Transmission Control - Forwarding Rules - Virtual Server, enable NAT DMZ service, set the host address to the local area network address, choose your own server name, set both the external and internal ports to 5002, select TCP / UDP as the service protocol, and set the server IP to the local area network address. Enable the rule and save the changes, as shown in Figure 4.

[0094] As shown in Figure 5, when operating the test software, after the test cable is connected, turn on the power of the two test units, and use a network cable to connect the measurement unit to the computer. After the measurement unit is successfully connected to the laptop, the "RCD3 Capacitive Device Critical Care Monitoring System Software" can be run for testing.

[0095] As shown in Figure 6, the system needs to be configured during this test. Select "Remote Parameter Settings" in the menu bar, and click "Timing Parameter Settings" to open the timing parameter settings interface. First, obtain the system time of the reference unit and the measurement unit. If the two are inconsistent with the computer system time, click the "Synchronize with Computer" button to synchronize them with the computer time.

[0096] If the address of the receiving server changes when transmitting data remotely, the new server address must be set in the server address field and kept. Other parameters do not need to be changed. The password should be set to "rcd3".

[0097] The instrument's "internal parameter settings" and "external parameter settings" have been calibrated before leaving the factory. Do not change them arbitrarily, otherwise it will affect the measurement accuracy.

[0098] After configuration, select "Remote Parameter Settings" from the menu bar, then click "Start Timed Monitoring" to bring up the online monitoring parameter settings interface, as shown in the figure below. Click the "Communication Test" button in the lower left corner to test the communication quality between the current measurement unit and the reference unit; click the "Get Initial Measurement Data" button to perform a measurement to verify the wiring and settings are correct. If the initial measurement data is normal, click the "Start Timed Monitoring" button to enter the timed monitoring mode.

[0099] S3. Calculate the stable information to obtain the dielectric loss.

[0100] As shown in Figures 1-6, the insulation status of abnormal equipment can be monitored in a timely manner, reducing the risks to power grid operation caused by equipment operating with defects; it can replace the periodic retesting of abnormal equipment, saving a lot of manpower and resources; it can reduce the personal risks during the retesting of abnormal equipment; it can achieve the effect of online monitoring, saving costs; it is mobile and can be used in rotation at multiple substations.

[0101] It is important to note that the constructions and arrangements of this application shown in several different exemplary embodiments are merely illustrative. Although only a few embodiments are described in detail in this disclosure, those who consult this disclosure will readily understand that many modifications are possible (e.g., changes in the size, dimensions, structure, shape, and proportions of various elements, as well as parameter values ​​(e.g., temperature, pressure, etc.), mounting arrangements, use of materials, color, orientation, etc.) without substantially departing from the novel teachings and advantages of the subject matter described in this application). For example, an element shown as integrally formed may be composed of multiple parts or elements, the position of elements may be inverted or otherwise altered, and the nature or number or position of discrete elements may be changed or altered. Therefore, all such modifications are intended to be included within the scope of the invention. The order or sequence of any process or method steps may be changed or rearranged according to alternative embodiments. In the claims, any "device plus function" clause is intended to cover the structure described herein that performs the function, and not only structurally equivalent but also equivalent in structure. Other substitutions, modifications, alterations, and omissions may be made in the design, operation, and arrangement of the exemplary embodiments without departing from the scope of the invention. Therefore, the present invention is not limited to the specific embodiments, but extends to various modifications that still fall within the scope of the appended claims.

[0102] Furthermore, in order to provide a concise description of exemplary embodiments, not all features of actual embodiments (i.e., those features that are not relevant to the currently considered best mode for carrying out the invention, or those features that are not relevant to implementing the invention) may be omitted.

[0103] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A capacitive device for critical care monitoring, characterized in that: include, The measurement unit includes a data acquisition module and a conversion module electrically connected to the data acquisition module; The processing module is electrically connected to the measurement unit; as well as, An output module electrically connected to the processing module.

2. The capacitive device for critical care monitoring according to claim 1, characterized in that: The transformation module includes a resistor module R and a surge arrester F electrically connected to the resistor module R; The output terminal of the surge arrester F is electrically connected to the acquisition module.

3. The capacitive device for critical care monitoring according to claim 2, characterized in that: The acquisition module includes a current transformer (CT) and an analog-to-digital converter (A / D) electrically connected to the output terminal of the current transformer (CT). The input terminal of the current transformer CT is electrically connected to the input signal In and the output signal Ix, respectively. The acquisition module is configured in two sets.

4. The capacitive equipment critical care monitoring device according to claim 3, characterized in that: The input terminal of the processing module is electrically connected to the analog-to-digital converter (A / D). The processing module performs transformation processing using the FFT algorithm to obtain the fundamental phase Ph(ns) and the fundamental phase Ph(xs).

5. The capacitive equipment critical care monitoring device according to claim 4, characterized in that: The output module is used to calculate the phase difference Ph, wherein the formula for calculating the phase difference Ph is: Ph = Ph(xs) - Ph(ns); Next, the dielectric loss Tanδ is calculated using the following formula:

6. The capacitive equipment critical care monitoring device according to claim 5, characterized in that: The current transformer (CT) adopts a through-hole structure with a through-hole diameter of Φ25mm.

7. A monitoring method for a capacitive critical care monitoring device, characterized in that: Including the capacitive device for critical care monitoring as described in claim 6, the critical care monitoring device further includes the following steps: Install critical care monitoring devices to acquire monitoring information; The acquired detection information is processed to obtain stable information; The dielectric loss is obtained by calculating the stable information.

8. The capacitive equipment critical care monitoring device according to claim 7, characterized in that: When acquiring detection information, a monitoring duration threshold is set. If the monitoring duration is less than the threshold, it is judged as short-term monitoring; if the monitoring duration is not less than the threshold, it is judged as long-term monitoring.

9. The monitoring method of the capacitive equipment critical care monitoring device according to claim 8, characterized in that: Processing the acquired detection information includes the following steps: Choose between standalone measurement mode or online measurement mode; The steps of the single-machine measurement mode include: using a single critical care monitoring device for testing, and entering the single-machine test in the settings interface, selecting capacitive equipment or surge arrester according to the type of equipment being tested; The steps of the online measurement mode include: connecting a single critical care monitoring device and the operating equipment, entering the selection interface and setting it to synchronization mode.

10. The monitoring method of the capacitive equipment critical care monitoring device according to claim 9, characterized in that: When installing the critical care monitoring device, connect the side of the cable with the shielded grounding end to the current input terminal inside the critical care monitoring box, and connect the shielded grounding end to the grounding bolt of the critical care monitoring box; Remove the plug from the pre-drilled inlet hole at the bottom of the live test terminal box and install a waterproof connector; The other end of the signal cable passes through the waterproof connector of the live test terminal box and is connected to the terminal block therein; Tighten the waterproof connectors at the cable inlets of the live test terminal box and the intensive care monitoring box; After the cable connection is completed, open the shorting tabs and knife switches of the live test terminal box in sequence. Wiring steps for reference unit voltage input: After the critical care monitoring box is securely fixed, first connect the side of the cable with the shielded grounding end to the voltage input terminal inside the critical care monitoring box, and connect the shielded grounding end to the grounding bolt of the monitoring box; The other end of the signal cable is connected to the secondary terminal of the PT on the same busbar as the device under test. Tighten the waterproof connector at the cable inlet of the critical care monitoring box.

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